Experimental Research On Recycled Rubber Powder Modified High Strength Concrete

With the rapid development of economy, the deteriorating "black pollution" resulted from the increasing waste rubber had posed a threat on our living environment. At the same time, the high performance concrete was provided with high strength, high workability, high volume stability and high anti-permeability, so the trend of development from normal concrete to high performance concrete was inevitable. But its disadvantage such as high elastic modulus, low toughness and high brittleness could not be properly settled up to the present. If the waste rubber was mixed into high strength concrete, not only the waste rubber could be used rationally, but some properties of high strength concrete could be improved, and this kind of concrete could be used in some fields. Therefore, it was greatly significant to study the material properties of rubber modified high strength concrete.In this study, basic mechanical properties of high strength concrete with the additive composition of rubber powder replacing part of fine aggregates were investigated. The main contents were listed as follows:(1). The physical properties including density and slump of rubber powder modified high strength concrete were studied. In order to investigate the influence of the size and contents of rubber powder pose on the material performance of high strength concrete, this thesis adopted three kinds of rubber powder. The sieve number of rubber powder used in test was No.15, No.40 and No.60, and the amount of rubber powder used in concrete was 1%, 2% and 3% respectively.(2). The compressive properties including cubic compressive strength, axial compressive strength, elastic modulus and stress-strain relation of rubber powder modified high strength concrete were studied. Also the effects of rubber powder of different types and contents on compressive properties were investigated. The calculating formulas of cubic compressive strength and axial compressive strength, cubic compressive strength and elastic modulus were built.(3). The splitting properties including splitting tensile strength and flexural strength of rubber powder modified high strength concrete were studied. Also the effects of rubber powder of different types and contents on splitting properties were investigated. The calculating formulas of cubic compressive strength and splitting tensile strength, cubic compressive strength and flexural strength were discussed in this thesis.(4). The permeability of chloride ion was studied in this thesis. Test results showed that the capability of chloride permeability was improved with the addition of rubber powder in high strength concrete.